Basic concepts and definitions of lung mechanics. Types of Assisted ventilation in neonates, including CDP continuous distending pressure, CPAP, PEEP, Positive pressure ventilation, pressure control, volume control, Volume guarantee, Hybrid modes, Patient triggered ventilation, VTV, High frequency ventilation, HFOV, Non invasive ventilation, Bubble CPAP, HHHFNC , Surfactant INSURE , MIST , LISA , Periprem bundle, Weaning from ventilation, Extubation

1. Assisted/Mechanical
Ventilation
In Neonates
Basic Concepts
Advanced Techniques
July 2022
Ahmad Refaat, MD
First presented at Marriott Jeddah, 1997

2. ‫ال‬ ‫إنسان‬ ‫كل‬ ‫عنق‬ ‫في‬ ‫َين‬‫د‬ ‫لإلنسانية‬
‫يؤديه‬ ‫أن‬ ‫بد‬
،
‫قدسية‬ ‫و‬
، ‫أوفيه‬ ‫أن‬ ‫أحاول‬ ‫َيني‬‫د‬ ‫اإلنسان‬ ‫تكريم‬ ‫و‬ ‫الحياة‬
‫حان‬ ‫إذا‬ ‫حتى‬
‫الرحيل‬ ‫وقت‬
‫أفضل‬ ‫بعدي‬ ‫يأتي‬ ‫من‬ ‫حياة‬ ‫يجعل‬ ‫ما‬ ‫ورائي‬ ‫تركت‬
.

3. Commitment to Values :
1) Ethical practice / Ethical conduct
2) Integrity, Honor
3) Responsibilities and Rights
4) Respect
5) Patient dignity
6) Education
7) Innovation , Growth and Excellence
8) Communication and Team work

4. OBJECTIVES
• Basic lung functions and lung mechanics
• Acquiring basic Knowledge of how Ventilation works, how it
influences cardiorespiratory physiology, and how applying it in
daily clinical practice has proved its safe use and life saving
outcomes
• Highlighting important aspects of gas exchange, lung-protective
concepts, clinical use, and possible adverse effects .
• The use of conventional Ventilation in daily clinical practice in
lung recruitment, determination of the optimal continuous
distending pressure and frequency, and typical side effects of
different Modes.
• High Frequency Ventilation and Non invasive Ventilation , its
indications and its place in respiratory care and respiratory failure
in preterm and term neonates.

5. Lung Physiology, Lung Mechanics
Safe & effective ventilation requires understanding:
1) The disease & its usual course
2) Basic concepts of pulmonary physiology &
flow mechanics
3) Modes of ventilation - Advantages &
Disadvantages
4) Effect of ventilation on CVS

6. Achievement of optimal gas exchange with
minimal damage to lungs or interference
with circulation.
Ultimate Goal

7. Benefits
• Normalize PO2
• Normalize PCO2
• Expand Atelectatic alveoli
(Open Lung Strategy)
Complications
Hyperoxemia:
BPD , ROP
Hyperventilation:
Cerebral ischemia
Hypoventilation:
Pulmonary Vasoconstriction
↓ Venous return → ↓ CO
Hyperinflation of already
inflated areas → Barotrauma

8. Compliance
Elasticity
Compliant lung needs little pressure to expand
Non compliant = Stiff
Definition:
Pressure change
required to achieve Volume change

9. S-shaped Compliance curve

10. • The lesson is: Optimize Lung Volume
(Diaphragm between 8-9 posterior ribs on X-Ray)
Open Lung Strategy : Lung-protective ventilation
• Ensures even distribution of TV
• Ventilating collapsed lungs leads to Atelectrauma.
(damage from repeated opening and collapse)
• TV preferentially moves to open lung areas with
less resistance which require less pressure, causing
overexpansion , and Volutrauma/ Biotrauma
(Cytokines: TNF & IL-8) even with normal TV

11. Lung Volume
(Restrictive Disease)
Lung Volume
(Obstructive Disease)
R D S ( H M D )
Pulmonary Hypoplasia
Tension pneumothorax
Effusion
Interstitial edema
Interstitial emphysema
M A S
Inverted I/E
with rapid rate

13. RESISTANCE
Friction between
moving
gas molecules
gas molecules
& airways
Nasal resist.2/3, ETT 1/2

14. Between moving gas molecules
Laminar Flow Turbulent Flow
ETT 2.5 flow < 3 L ETT 2.5 flow > 5 L
3 < 7.5 L 3 > 10L

15. Newer ventilators adjust Flow automatically
Operator chooses the shape of the Wave :
Slope as in Drager Babylog VN500
Square or Sine as in Newport
Rise Time as in GE

16. Flow Rate:
High 4-10L/min
10
20
30
1 sec 1 sec
Square Wave Sine Wave
1 sec
1 sec
Low < 3L/min
Drager Babylog 8000

17.  Resistance   pressure delivered to baby
  volume
* Airway or tube length, diameter, Dead Space
* Density of gas : Mixture of Helium 80%
O2 20% is 1/3 the resistance of room air

18. Work of breathing:
The force generated to overcome resistance forces that
oppose volume expansion & gas flow during
respiration. Example: Opening collapsed alveoli in
RDS, Mechanical obstruction with plugs in MAS.
If WOB > O2 to muscles
 Switch to anaerobic   blood lactate levels
 Metabolic Acidosis
Strength & Endurance:
In Diaphragm, Preterms have 9.7% type I fibers (slow-
twitch, high-oxidative), Full-terms 25 %.
Intercostal muscles, Preterms have 19.0 % type I
fibers, Full-terms 45.7%

19. Time Constant
Measure of how long it takes for alveolar
& proximal airway pressures to equilibrate.
 Compliance   time constant
 Resistance   time constant
Delivery of pressure and volume is complete in
three to five time constants
( Choice of Ti & Te )

20. Inadvertent PEEP
Auto Peep, Intrinsic Peep

21. Signs of Air Trapping
1) Overexpansion : Best seen from side,  AP distance
2) X-Ray : Flat ribs, diaphragm below 9th posterior rib
3)  Chest wall movement despite good breath sounds
4) CO2 retention not responding to  rate

22. (cont.)
5) CVS compromise: -  CO
-  BP
- Metabolic acidosis
-  CVP
- Mottled skin

23. During Early RDS :
 Compliance N Resistance  Time constant
Up to inverted I/E ratio, with no fear of Air trapping
During Recovery phase:
Compliance  Time constant 
To avoid Air Trapping
 I/E ratio , same Ti ,  TE

24. Changes in Ventilator
Setting
To  risk of Air Trapping:
* RR *  PIP & PEEP *  T1  TE
Theoretically :
* PEEP  expansion  Compliance 
 Time Constant  emptying.
* PEEP   P   VT

25. Hypoventilation
Causes:
1) CNS depression
2) Respiratory muscle weakness, fatigue,
denervation
3) Hypoplastic lung
4) Restricted expansion: Pneumonia,
Pneumothorax, Emphysema
5) Airway obstruction
Side effects : Pulmonary Vasoconstriction

26. Hyperventilation
Causes:
1) Attempt to compensate for metabolic acidosis
2) Attempt to compensate for hypoxemia.
3) Limited atelectasis or pulmonary infiltration
Side Effects:
1)  muscle excitability secondary to reduction of Ca++
2) Shift to left 02 dissociation curve :  Oxygen to tissue
3) Cerebral Vasoconstriction Ischemia
Hypoxemia

27. Oxygen Saturation
Ratio of O2 bound Hg (OxyHg) to total Hg.
SaO2 88-92% is adequate in early New Born period
Extreme preterms O2 requirements are around 50
or SaO2 90%
O2 transport and delivery to tissues depends on:
* O2 saturation * Mean BP

28. To improve PaO2
Theoretically
1)  PAO2 2) Optimizing Lung Volume
3) Maximizing PBF 4) Optimizing V/Q
Clinically
1) FiO2
2) MAP ( function of PEEP, PIP, Flow, I/E )
3) Maintaining Normal pH

29. Control of Variables of
Ventilation
1) Speed of pressure increase flow rate
2) Height of inflation press. wave PIP
3) Duration +ve press. Ti
4) Minimum press. at end exp. PEEP
5) Number of press. waves Rate
6) Oxygen: Most commonly used drug in NICU

30. Frequency
 Rate   VE (Minute Ventilation)
 PCO2  pH  Pulmonary blood flow  PO2
…………
Experimentally:
With I/E 1:2 & press 17/2
Rate from 30  60  PO2  PCO2, -- FRC, PEEP no
change
60  120 PO2 , PCO2 no change
55% FRC, 60% PEEP
 in FRC without  PO2 reflects overdistension from
inadvertent PEEP

31. Continuous Distending Pressure: CDP
Maintain  transpulmonary press. during expiration
CPAP  Spontaneous breathing
PEEP  Assisted ventilation
Best PEEP : Normalize Lung Volume
Correct ventilatory insufficiency
Atelectasis  FRC  V/Q mismatch
 Intra pulmonary shunt  Pulmonary edema
Open Lung Strategy
Open Lungs and Keep them open

32. TYPES OF CDP
- EndoTracheal/Pharyngeal CPAP(old,rarely used)
- Bubble NCPAP: Applies pressure via a nasal
mask, forming tight seal to minimize leak.
Pressure fluctuates 4 cm around mean submerged
in water.
- Humidified Heated High Flow Nasal Cannula
HHHFNC : Delivers flows from 1- 8 L/min
Less trauma to nares, simpler application, easier to
care and access baby (skin to skin contact)

33. Indications of NCPAP
• Respiratory Distress Syndrome (RDS)
• Pulmonary edema. . Atelectasis.
• Recent extubation.
• Transient Tachypnoea of the newborn
(TTN)
• Tracheomalacia or similar disorders of the
lower airway.
• Apnea of prematurity.

34. Failure criteria for NCPAP
PaO2 < 50 in FiO2 >
0.6
PaCO2 > 60
pH < 7.2
On Maximum acceptable settings:
PEEP > cm H2O
• Air leak on NCPAP
• Recurrent apnea on NCPAP despite caffeine
citrate or aminophylline, > 6 / Hour, or
severe apnea requiring IPPV

35. Indications of HHHFNC
• Infants with Chronic Lung Disease
• As a mode of weaning NCPAP support
• Alternative to NCPAP in mild/moderate
respiratory distress, for more mature infants.
• Alternative to NCPAP for post-extubation
support for more mature infants (above 28
weeks)
• Post-operative respiratory support.

36. Indications of HHHFNC (cont.)
• Babies with nasal trauma from NCPAP
• Treatment or prevention of apnea of
prematurity.
• Consider HHHFNC when CPAP 4-6 cm
H20 and Oxygen requirements < 0.4
*Contraindication: Frequent apnea (despite
caffeine in preterms)
*Potential Disadvantage: Gastric distension

37. Pulmonary effects of CDP
Open Lung Strategy
Air splint . The lower the lung compliance, the less
transmission of PEEP to intrathoracic structures.

38. Cerebral effects
PEEP  intrathoracic pressure
Direct inter - vertebral foramina CVP
to the thoracic dura
 ICT
 Cerebral perfusion pressure IVH

39. Disadvantages of CDP

40. Criteria for Initiation
1) Hypo Inflation 2) PO2 < 50 in 60% O2
CPAP 4 cm H2O by 2 cm up to 8 – 10 cm
No response : O2 by 5% increments
Optimal CPAP: Max O2 with least FiO2
& without PCO2
NCPAP failure
PO2 < 50 in 60 % O2 with CPAP 8 - 10 cm
PCO2 > 60 PH < 7.2

43. Positive Pressure Ventilation
Volume control VCV Pressure control PCV
Volume is set
TV constant
Pressure varies with
Compliance/Resistance
Over distension of
healthy areas promotes
air leak
Pressure is set
Pressure constant
Volume varies with
Compliance/Resistance

44. O2
Neurologic injury
PPHN
appropriate O2
Relieves hypoxemia
dilates pulmonary vasc.
O2
ROP
BPD
Ventilator Controls
1) O2 /FiO2 2) PIP
3) PEEP 4) Rate
5) Flow/Slope/Waveform 6) I:E
7) TV in Hybrid Modes (VG, VTPC, PRVC)
FiO2: O2 is the most commonly used drug in NICU

45. PIP Peak Inflation Pressure
Determines TV
Changes with flow , Rate , I:E
Use lowest PIP that ventilates
Strategy of Low Press, Short Ti, Medium to High
Oxygen, High Rate … High MAP
Barotrauma should be avoided at all cost
Permissive Hypoxemia PO2 as low as 45-50
Sat > 𝟗𝟏 in Preterms < 𝟐𝟖 weeks
Permissive Hypercarbia PCO2 55- 60
pH as low as 7.2 for brief periods.
Avoid swings in PCO2 & severe Hypoxia

46. Low press. < 20 - 25 High press. > 25
PAL, BPD
 Ventilation ( PCO2 -
 PO2)
Atelectasis
Expand Atelectasis
 PO2 ,  PCO2
 Pulm. Vasc. Resistance
 PAL , BPD
 VR ,  CO

47. Rate

48. Slow (40/min) Med (40-60)R Rapid > 60
Physiological
No air trapping
doesn't exceed
Time Constant
May not provide
enough
ventilation in
some cases
 PO2,  PCO2,
allow  PIP
used in PPH,
atelectasis 
Inadvertent
PEEP
Ti shorter than
Time constant ➞
Air trapping.
Very high rate:
Inadequate
ventilation: only
dead space vent.

49. Inverted > 1:1 N 1:1 1:3 Prolonged < 1:3
MAP , PO2 
Better distribution
of air
Air trapping
 VR,  CO
PVR 
Worsen PPH
Worsen PAL
Physiologic Weaning
MAS
Short Ti  TV
inadequate ventilation
ventilates dead space
I:E

50. SINE WAVE SQUARE WAVE
Physiologic
 BPD
Smaller tubes , 2.5
Slow rate
Higher MAP for equiv. PIP
Expands atelectatic alveoli
Bigger tubes , 3 – 3.5
Higher rate
Better V/Q
MAP: a function of PIP, PEEP, I : E , Waveform.

51. Oxygenation Index
OI
• Used to assess severity of Hypoxic Respiratory
failure in ventilated babies
• A higher value = Sicker lungs
• OI = MAP X FiO2 X 100 / PaO2
• Oxygen Saturation Index OSI
• OSI = MAP X FiO2 X 100 / SpO2
• Mild 5-10. Moderate 11-15. Severe > 15

52. Respiratory Failure
Criteria of starting Ventilation
2 or more of
Clinical: 1) Retractions , Grunting
2) RR > 60
3) Intractable apnea > 6 / Hour, or
severe apnea requiring IPPV
Laboratory: 1) PO2 < 50 in 60% O2 ( Hypoxic)
2) PCO2 > 60 ( Hypercapnic)
3) PH < 7.2

53. RDS/ HMD
Compliance   PIP
Resistance N
Time constant  (0.15s) ( I:E 2:1 )
FRC   PEEP
V/Q    PEEP
Strategy: PIP 16 – 20 - 25
PEEP 4 - 5
Rate 60 - 80
I:E 1:1
Flow 5 ETT 2.5
8 ETT 3
FiO2 60 - 80 %
TV 4 - 6 - 8 ml/kg

54. MAS
Compliance -/  PIP
Resistance   PIP, Ti 
Time constant   Ti,  Te
FRC   PEEP,  Te
V/Q   PEEP
Strategy: PIP 22-25
PEEP 2-4
Rate 40
I:E 1:2
Flow 4 ETT 2. 5
6-8 ETT 3
FiO2 60-80% (up to 100)

55. Guidelines of Ventilator
Setting
FiO2 PEEP PIP Rate
100% 7-10 30-35 60
70% 5-6 25-32 55
50% 4 22-30 50
40% 3-4 18-25 40-45
30% 3 15-22 30

56. Assessment MCQs
1- Hyperventilation causes Cerebral vasoconstriction
True False
2- Hypoventilation causes pulmonary vasoconstriction
True False
3- Best PEEP optimizes lung volume between 8-9 post ribs
True False
4- Delivery of pressure and volume is complete in 3-5 TC
True False

57. Assessment MCQs

59. Patient Triggered Ventilation
Volume Targeted Ventilation
Non Invasive Ventilation

60. NEONATAL VENTILATORS
* Time Cycled: Cycle from Inspiration to
Expiration at a pre set Inflation time Ti
*Pressure Limited: Reach pre set pressure
(PIP) before end of Inflation time
* Trigger : Signal from baby, detected by
ventilator as starting spontaneous breath.
Pressure or Flow, Flow more sensitive
* Flow Cycling: Inflation ends when Flow
drops to 5-10-15% of original Peak flow.

61. Trigger
Spontaneous Inspiratory effort 
-ve deflection of Pressure ,
or increase in Flow. This initiates a ventilator Inflation
Termination of Ventilator Inflation:
Time cycled modes (SIMV - A/C) , End point of
ventilator Inflation is reaching pre set Inflation time Ti
Flow cycled mode (PSV) , End point of ventilator
Inflation is  of Inspiratory Flow to 15% of original
Peak flow.

62. Patient Triggered Ventilation
Asynchrony results in :
1) Insufficient gas exchange , baby fighting ventilator:
baby exhaling against ventilator inflation
baby inhaling against ventilator expiration
2) Air trapping, Pneumothorax
3) In preterm, irregular BP & CBF  IVH

63. Synchronised Ventilation Modes
Initiate Mechanical breaths (Inflation) in response to a
signal (Trigger) delivered from the baby representing
the start of spontaneous respiratory effort
( Ventilator kick )
Basic Modes :
1) SIMV Synchronized Intermittent Mandatory
Ventilation
2) A/CV (SIPPV) Assist/Control Ventilation
3) PSV Pressure Support Ventilation

64. SIMV
Time cycled Mechanical breath (Inflation) is
initiated in response to onset of baby’s
Inspiratory effort
Result: Supported breaths at a pre set Rate
Constant Rate
Full Inspiratory synchrony
Possible Expiratory synchrony

65. A/C Ventilation
SIPPV
Time cycled Mechanical breath(Inflation) is initiated in
response to the onset of baby’s Inspiratory effort (Assist)
OR
Initiation of a Mechanical breath (Inflation) at a regular
Rate if the baby fails to spontaneously breathe (Control)
Result : Each spontaneous breath supported
Variable Rate
Full Inspiratory synchrony
Possible Expiratory synchrony

66. A/C Ventilation
A/C Ventilation A/C Ventilation
with Flow Cycling

67. PSV
Flow cycled mode
Flow Cycling determines end of baby’s inspiratory effort
with or without Time cycling
Result : Each spontaneous breath supported
Variable Rate
Full Inspiratory / Expiratory synchrony
Control of ventilation is patient-driven.
Ventilator controls Pressure and Oxygen.
Patient controls Rate and Ti
Used independently or in conjunction with SIMV

68. PSV(cont)
Designed to assist baby's spontaneous effort with
a pressure boost
Needs
 Reliable intrinsic respiratory drive
 Back up minimum mandatory ventilation
in case of apnea ( Apnea setting )
Applications :
* Weaning mode with SIMV
* Rescue approach
* BPD

69. Clinical Applications
Which ventilation mode is best ??
Intrathoracic pressure is less with SIMV
than with A/C or PSV
This promotes venous drainage, CO , BP
A/C is the strongest mode, used in acute stage, at the start of
ventilation. Watch CO2 wash (Hypocapnia)
SIMV is the easiest Weaning mode
PSV is the most gentle mode for a fragile lung

70. Volume Targeted Ventilation
• Neonatal ventilators use Flow sensors at the Y piece
near ETT to measure Expiratory TV , unlike
Universal ventilators(neonate, pediatric and adult)
who measure TV at ventilator end of the circuit
ETV is more accurate, Leak is higher in inflation
• TV in Neonates 4 - 6 ml/kg
• MV 200ml/Kg to normalize Blood gas
400 - 500ml/Kg to Hyperventilate
• Operator chooses TV and a pressure limit
(15-20% higher than operating PIP)

71. Volume Targeted Ventilation
• Ventilator adjusts pressure up and down to
target set TV, using the lowest possible
pressure necessary to reach set TV.
• Smaller infants use higher TV/Kg , as fixed
dead space is proportionally larger
• Adjustments of TV are guided by PaCO2
• Extubation is attempted when Blood gas is
normal in TV 4 ml/Kg, and baby is not
tachypneic
• Set & Forget

72. Non Invasive Ventilation
• Interest in NIV modes is due to rising
incidence of BPD with use of MV.
• Bad Outcomes of BPD:
• Long-term Respiratory: airway obstruction,
airway hyperreactivity, and hyperinflation
• Neurologic: Cerebral palsy, movement
disorders, abnormal motor skill
development, visual and auditory disorders
• Leading to a poor quality of life, with
increased fatality risk

73. Non Invasive Ventilation Modes
• NIV is respiratory support through upper
airway without ETT
• Head Box
• Nasal Cannula
• HHHFNC
• NCPAP (Bubble)
• NIPPV
• SNIPPV
• BIPAP (rarely in Neonates)

74. NCPAP

75. NIPPV

76. NIPPV (cont.)

77. BiPAP
• Compared to NIPPV:
• Pressures lower
• High and low pressure difference 3-4 cm
• Longer Ti 0.5 - 1 second
• Lower Rates 10-30 / min
• Rarely used in Neonates
• Needs a special machine

78. HHHFNC
•  Airway resistance/ Work of breathing
•  Gas exchange by washout nasopharyngeal
dead space
• Positive distending pressure
•  Nasal trauma,  Infant pain scores
• Rising popularity: Ease of application

79. HHHFNC (Cont.)

80. Ventilator
Mode
Inflation
Trigger
Assist each
Breath
Ventilator
RR
Inflation
Time/ Ti
PIP Tidal
Volume
IMV NO No Fixed Fixed Fixed Variable
SIMV Yes No Fixed Fixed Fixed Variable
A/C Yes Yes Variable Fixed Fixed Variable
PSV Yes Yes Variable Variable Fixed Variable
PSV + VG Yes Yes Variable Variable Variable Fixed
A/C + VG Yes Yes Variable Fixed Variable Fixed
SIMV + VG Yes No Fixed Fixed Variable Fixed
Ventilator behavior in different Modes

82. If Invasive Ventilation,Which Mode ?
• Start with the stronger mode, A/C
• When blood gas show Hypocapnia,
Alkalosis, shift the bigger babies to PSV,
and the smaller babies to SIMV+PSV
• Wean PSV down to TV 4 ml/Kg
• Wean SIMV Rate down to 12-15/minute
• Post Extubation use NIV, then shift to
Bubble CPAP or HHHFNC

83. Starting Settings
Mode: A/CV or SIMV + PS
• Use VTV in all preterm neonates
• Use Pressure Control only in large ETT leak
(limiting reliable delivery of measured TV) or
VTV is not available
• Typically i initiate Ventilation with A/C and
reserve HFV for cases of refractory Respiratory
Failure despite high settings, and Air leaks

84. Starting Settings
Initial settings:
• TV 4 to 6 mL/kg(The higher TV for the smaller
babies, relatively bigger dead space)
• PEEP 5 to 6 cm H2O(Lung inflation Rib 8-9)
• Ti 0.35 to 0.4 seconds (Min 3-5 TC, check
Spontaneous Ti on PSV Mode)
• Rate A/C and PSV 40/min, SIMV 60/min
• Slope short. Flow enough to produce Square wave
• Oxygen 40-50% (enough to keep Sat 92 - 94)

85. Weaning
• Improvement of disease being treated
• Begin with the most toxic to lung: PIP, Oxygen
• Wean slowly, allow Neonate to adapt and
gradually assume responsibility for gas exchange
• Physiologic homeostasis (HCT > 40)
• Nutritional support
• Shift to SIMV+PS mode, Wean PS, then SIMV
•  PIP 2 cm H2O, FiO2 5%, Rate 5 BPM.
• SaO2 and TcPCO2 monitoring facilitate weaning

86. Extubation
Objective Measurements
• Adequate Oxygenation (PO2 ≥ 60 mm Hg in FIO2
≤ 0.3; PEEP 5 cm H2O; PO2/FIO2 ≥300)
• Improved Compliance on Pressure/Volume loops.
• Minimal pressure support (PIP 5-10 above PEEP)
• MAP (PAW) ≤ 5
• Increased urine output, Diuretic phase of RDS.
• Low PaCO2 allows decreasing PIP, PEEP, Rate,
and Mode change to SIMV

87. • SIMV rate < 15
• Stable CardioVascular system(HR 100-160;
Stable BP; Minimal/No Inotropic support )
• Resolved Respiratory Acidosis, pH ≥ 7.25
• Normal electrolytes, No fluid overload
• Good respiratory drive/effort
• Awake, Adequate muscle tone,
• No Sedative infusions
• Extubate to NIV, Bubble CPAP for Preterms,
then HHHFNC, then room air
• Extubate to HHHFNC for Terms, then room air

88. The story
What to do for best possible outcomes

89. PERIPrem bundle (cont.)
- Early Breast Feeding
- Volume Targeted Ventilation
- Caffeine
- Prophylactic Hydrocortisone
- Probiotics
- IntraPartum Antibiotics prophylaxis
- Failure to receive antenatal dexamethasone, PDA,
Hydrocortisone IV for neonatal hypotension, and low
hematocrit in the first 3 days of life is associated with
severe IVH in VLBW neonates.

90. Surfactant
Traditional ETT + NGT administration+MV
is largely replaced by the less invasive
INSurE / MIST / LISA + NIPPV
INSurE
Intubate, Surfactant, Extubate
MIST
Minimally Invasive Surfactant Therapy
LISA
Less Invasive Surfactant Administration

91. MIST/LISA Surfactant
• Babies 29 - 32 weeks
• Uses thin catheter inserted in trachea to
deliver Surfactant
• During procedure baby is breathing
spontaneously, supported by CPAP
• Given over 2-3 min,
• Decrease rate if Hypoxia or Bradycardia
• Target O2 Sat 89-95

92. Prophylactic Vs Rescue

93. Lung protective strategies
minimizing VILI
• MV is a dynamic process, the good intensivist is
in a state of continuous Weaning from Ventilation
• VILI: Ventilator-induced lung injury
• Avoid MV through use of NCPAP when possible
• Failed NCPAP requires intubation and MV

94. Lung protective strategies
• Lung protective strategies include:
– VTV with TV 4 to 6 mL/kg to minimize volutrauma
– PEEP to maintain Lung recruitment / avoid atelectasis
- Avoid high FiO2
- Acute stage Target blood gases: accept lower Oxygen
40-50 and permissive hyperCapnia, CO2 50-60
- Use HFOV in neonates at high risk of developing
VILI or as Rescue therapy for neonates with refractory
Respiratory Failure while on Conventional MV

95. Assessment MCQs
1- In SIMV Supported breaths is preset at a Constant Rate
True False
2- In A/C and PSV each spontaneous breath is supported
True False
3- In A/C and PSV Rate is variable
True False
4- In VTV operator TV is fixed , Pressure is variable
True False
5- NIV decreases incidence of BPD
True False

97. HIGH FREQUENCY VENTILATION

98. HFV
A type of ventilation that :
- Uses tidal volumes less or equal to dead
space volume
- Delivers volumes at rates much higher
than physiologic rates

99. HFV
Advantage: Delivers adequate minute volume with
lower proximal airway pressure
HFPPV HFJV HFOV
Enhance diffusion & distribution of respiratory gas
 CO2 elimination
Optimum operating frequency = Max CO2 elimination.

100. Atelectasis is a common problem during low TV
constant airway pressure ventilation:
Use PEEP MAP
or Background CMV or Sigh rate
To keep Lungs open

101. Clinical Guidelines:
2 Strategies
Limiting pressure exposure Optimizing lung volume
Air leaks Atelectatic disease
Obstructive disease
Restrictive disease

102. HF PPV
Conventional MV (CMV) operating at 60 - 150
Inflation/min. Usual Max rates 75-100
Adequate respiratory support in RDS with fewer
pulmonary air leaks
Hi Rate, Moderate Oxygen, Moderate PEEP, Low PIP
Strategy

103. HF PPV(cont.)
Limitation: all Vents have max operating frequency beyond
which Minute Ventilation , FRC 
Ti < 3 time constant TC  Tidal Volume
Te < 3 time constant TC  Lung emptying
 FRC, Air trapping (Inadvertent PEEP, Auto PEEP)
• In time-cycled A/C, rapid breathing results in shortening
of the expiratory phase because the inspiratory phase is
fixed. Resulting in Air trapping.
• Flow cycling avoids that

104. HFJV
Operating at rates 240-660/min
Deliver short pulses of pressurized gas into upper
airway through jet injector
 CO2 at lower peak pressure & MAP

105. HFOV
Airway vibrators / Oscillators
Operating rates 300 - 900/ min
5 - 15 Hz
(1 Hz = 60 breaths/minute)
Active inspiration & active expiration

106. Oxygen Control / CO2 Elimination
HFOV
• HFOV clearly separates control of Oxgenation
and CO2 elimination
• Oxygenation: controlled by
FiO2 , and MAP (Keeps Lung open)
• Ventilation / CO2 Elimination: controlled by
- Pressure Amplitude (∆ P):
Higher ∆ P generates larger TV
- Frequency : Lower Frequency generates larger TV
- I:E ratio 1:1 generates larger TV than 1: 2

107. Ventilation / CO2 Elimination
• ↑ ΔP = ↑ tidal volume = ↑ CO2 removal
• ↓ frequency = ↑ tidal volume = ↑ CO2 removal
• I:E 1:1 = ↑ tidal volume = ↑ CO2 removal
• ↑ frequency HFOV-VG = ↑ tidal volume = ↑ CO2
removal
Oxygenation
• ↑ MAP = ↑ PO2
• ↑ FIO2 = ↑ PO2

108. Indications for HFV
Barotrauma: Pulmonary air leaks.
• Pneumothorax
• Pulmonary Interstitial Emphysema (PIE)
Respiratory failure :
unresponsive to conventional ventilation
Extreme Preterm: HFOV-VG

109. Pulmonary air leaks
HFV
Produces smaller pressure fluxes within the distal airways.
Gas is delivered distally at a constant distending pressure.
Less stretching of injured tissues during peak inflation
Less gas escaping during peak inflation.

110. Indications for HFOV
• Inadequate oxygenation that cannot be safely treated
without potentially harmful ventilator settings and
increased risk of VILI. (Ventilator Induced Lung Injury)
• Respiratory Failure in spite of high Ventilator setting:
– Peak inflation pressure (PIP)
> 25 Preterm > 28 Full Term
– FiO2 1 (Oxygen 100%) or inability to wean
– Mean airway pressure MAP (Paw) > 15 cm H2O
– Peak end expiratory pressure (PEEP) > 6 cm H2O
– Oxygenation index > 15
– OI = MAP × FiO2 × 100 / pO2

111. Indications for HFOV
− Failed Conventional Ventilation *
– Air leak *
– PPHN *
– Congenital Diaphragmatic Hernia *
– RDS/ARDS
– Meconium aspiration
– BPD
– Pneumonia
– Lung hypoplasia

112. Switching from Conventional to HF Ventilation
– Memorize CMV MAP
– Reduce CMV rate to about 3 - 5 bpm or switch
to CPAP
– Set MAP 2 - 4 cmH2O above operating CMV MAP
– Increase MAP step by step until oxygenation
improves and the lungs become optimally inflated
– Optimal inflation between 8 and 9 posterior ribs
on X-Ray

113. Initial Settings
1) Mean Airway Pressure (MAP): Starting MAP is
set 2 - 4 cmH2O above current CMV MAP.
• Stepwise increase in MAP of 1-2 cmH2O every 5-10
minutes , to achieve lung recruitment.
• MAP is increased until optimal oxygenation is reached, or
until signs of CVS compromise ,  CO , become evident
(Tachycardia, Hypotension)
• TcM monitoring (Oxygenation, CO2 clearance, HR and
BP), X-Ray to avoid Hyperinflation and Air leaks

114. Initial Settings MAP
• Oxygenation-guided lung recruitment requires
continuous monitoring of oxygen.
• Pulse oximetry , Transcutaneous pO2 are good options
• Typical operating range for MAP is 10 to 16 cmH2O.
• Use higher MAPs in severe lung disease with poor
compliance
• Use lower MAPs in severe air trapping or air leak

115. Initial Settings
2) Amplitude (ΔP): Set at 1.5-2 times the value of MAP,
sufficient to see a chest vibration “wiggle” from nipple to
umbilicus. Amplitude can be reduced after lung
recruitment, to avoid hypocarbia.
• Continuous transcutaneous monitoring, TcM of PCO2 or
DCO2 , guide ΔP and frequency adjustments.
• Typical operating range for ΔP is 20 - 30 cmH2O
• Use higher ΔP with caution in severe lung disease.

116. Initial Settings
DCO2 (Carbon Dioxide diffusion coefficient)
DCO2 = VT2 X F (value on ventilator software)
Best predictor of CO2 elimination in HFOV
↑ DCO2 = ↑ CO2 removal
A sudden drop in values is usually an early sign of
impaired ventilation, requiring attention , displaced
tube, blocked tube, suction…

117. Initial Settings
3) Frequency/Hertz: Usual starting frequency is set
at 10 Hz. Lower frequencies 6-8 Hz may be used in
severe lung disease, with poor CO2 clearance,
especially in term infants.
Usual starting frequency in Preterm is 12-15 Hz
4) I:E Ratio: Usually 1: 1 to 1: 2 in special
circumstances (e.g. severe air trapping).
5) IMV Rate (sighs): Previous conventional PIP,
Inflation time 0.4 - 0.6 seconds , Rate 4 / Minute

118. HFOV-VG
• Clinician sets : A predefined tidal volume (2ml/kg)
• A maximum amplitude ~20% above the amplitude
currently used
• The ventilator delivers the required amplitude (up to the
predefined maximum amplitude) to achieve the set tidal
volume.
• Using VG with HFOV leads to more consistent and stable
arterial pCO2 (40 to 55 mm Hg), and hence a more stable
cerebral blood flow.

119. HFOV-VG(cont.)
• The strategy is to set the volume target (Volume
Guarantee) appropriate to the selected frequency for
oscillation
• Studies show a greater CO2 elimination efficiency at
higher frequencies in HFOV-VG
• Approximate tidal volumes required at different
frequencies
• Frequency (Hz) 5 7.5 10 12.5 15
• VT (mL/kg) 2.8-3.5 2.3-2.7 2.0-2.5 1.8-2.35 1.6-2

120. Ventilation
• CO2 wash in HFOV is controlled by Amplitude, and Oscillation
Frequency. Decreasing frequency can cause marked drop in CO2 ,
except in HFOV-VG
• If  pCO2  Amplitude ,  Frequency
• If  pCO2  Amplitude ,  Frequency
• Typical operating ranges for ΔP (amplitude) is 20 - 30 cmH2O.
• Higher ΔP (amplitude) is used in severe lung disease.
• Always observe chest wall vibrations.
• Blood gas should be checked 20 minutes after a change in settings.

121. Problem HFV Adjustment
-Atelectasis, Hypoxemia,
Hypercapnia
-Hyperinflation, Hypoxemia,
Hypercapnia
-Hypercapnia without
Hyperinflation
-Increase MAP
-Decrease MAP
-Increase Amplitude
-Decrease Frequency if already
using max Amplitude

122. Problem HFVAdjustment
- Hypocapnia
- Hyperoxemia
- Decrease Amplitude,
Increase Frequency if
already using minimum
Amplitude
Decrease FiO2, MAP

123. WEANING
• Adjust Amplitude +/- Frequency (Hz), as CO2 clearance
improves, to avoid hypocapnia.
• Maintain the lung volume during weaning.
• Reduce Oxygen as tolerated, and once less than 30 – 40%,
wean MAP 1-2 cm H2O.
• In air leak syndromes, reduce MAP first
• Reduce Amplitude 2-4 cm H2O at a time, according to the
pCO2. Remember to confirm vibration.
• If an acceptable pCO2 cannot be maintained by adjusting
the Amplitude alone then adjustments to the frequency
(Hz) may be required.

124. WEANING
• Deterioration in oxygenation may be due to either a
MAP which is too low (atelectasis), or too high (over
distension during the baby’s recovery phase).
X-Ray confirms
• Patients may be extubated from HFOV to CPAP.
• Alternatively to conventional ventilation prior to
extubation.
• When changing to conventional ventilation set an
appropriate PEEP and then choose a PIP to give a
MAP 1 - 2 cm H2O below the HFOV setting.

125. WEANING
pCO2 N
Start with MAP if
pO2 N in 60% O2
Start with  P if pCO2 sub N
MAP threshold = 8 - 10 cm H2O
Back to CMV

126. Complications of HFOV
• ATELECTASIS: a common problem in low TV constant airway
pressure ventilation
TTT : increase Rate or PIP of IMV breaths(sighs).
Increase PEEP/MAP
• INCREASED MOBILIZATION OF SECRETIONS:
TTT : increase frequency of suctioning of ETT as needed
• HYPOTENSION:
TTT : lower MAP by decreasing PEEP, after failure of volume and
positive inotropes .

127. Assessment MCQs
1- Indications of HFOV include all except
- Peak inspiratory pressure (PIP) > 25 in Preterm
- Peak inspiratory pressure (PIP) > 28 in Full Term
- Oxygenation index > 15
- Mean airway pressure MAP (Paw) > 15 cm H2O
- Atelectasis
2- Hypercapnia with Hyperinflation, the correct action is
- Increase MAP - Decrease MAP
3- Hypercapnia without Hyperinflation, the correct action is
- Increase Amplitude - Decrease Rate

128. Assessment MCQs
4- In Hypocapnia , the correct action is
- Decrease Amplitude
- Decrease Rate
- Increase MAP
- All of the above
5- In Weaning, start with MAP if
- pCO2 Normal - pCO2 sub Normal
6- In Weaning, start with Amplitude if
- pCO2 sub Normal - pO2 Normal in 60% O2

129. Suggested References
• Cloherty and Stark's Manual of Neonatal Care,
9th Edition, 2022
• Gomella’s Neonatology 8th Edition 2021
• https://emedicine.medscape.com/article/979268-overview#a5
• https://pubmed.ncbi.nlm.nih.gov/?term=high+frequency+ventilation
+in+neonates
• https://www.clinicalguidelines.scot.nhs.uk/
• https://www.evidence.nhs.uk/
• https://www.weahsn.net/our-work/transforming-services-and-
systems/periprem/
• https://www.nature.com/
• Assisted Ventilation of the Neonate, Elsevier , 7th Edition, 2022
• Manual of Neonatal Respiratory Care , Springer , 5th Edition, 2022